Gabrielle Giffords, the congresswoman who survived being shot through the head, can now breathe on her own, her doctors said as the families of others killed and maimed by deranged gunman recounted tales of heroism and heartbreak.

One of the six killed, Dorwan Stoddard, 75, threw his 75-year-old wife to the ground and then spread-eagled himself atop her as a human shield.

"He heard the shots and covered my mom with his own body," Penny Wilson said. "It was a beautiful way to say goodbye."

Another daughter, Angela Robertson, said the two were once sixth-grade sweethearts but had had 40-year marriages to other people. They were widowed within a year of each other, reintroduced, and 15 years ago fell in love again. "What a way to go, as a hero," Ms. Robertson said.

In emotional, sometimes heartrending accounts - punctuated by pauses as tears nearly flowed - families of some of the victims whose tragedies have been largely overshadowed by the media focus on Ms. Giffords spoke of shattered lives and hard roads ahead.

"My wife Suzie was the parent who took Christina Taylor Green to this event," said Bill Heilman, referring to the nine-year-old who was the youngest of the victims. Mr. Heilman described how he had to tell his wounded wife, shot three times but expected to recover, that the little girl she treated as a granddaughter had been killed.

"Christina! Christina! Let's get out of here!," Mrs. Heilman still screams as she wakes from the morphine haze, said her husband, adding that the little girl's parents were close family friends and neighbours. She had offered to take the little girl to Ms. Giffords's "Congress on Your Corner" session with constituents because the third-grader had just been elected to her elementary school's student council.

"Suzie had been looking for an event they could share together ... it was a magnificent chance to provide a positive female role model for Little Christina," said Mr. Heilman.

"She keeps talking about holding hands and saying that the bleeding was profuse," he said, adding that his he knew his wife faced a long struggle with the psychological trauma of knowing she took a little girl on an outing that ended in death. Mrs. Heilman faces a long, slow recovery. One bullet shattered her hip.

Her first words to her husband were: "What happened to Christina?" Mr. Heilman said, adding that on the advice of hospital counsellors he had told her their surrogate granddaughter was dead.

"Suzie and Christina were generations apart but very much birds of a feather," he said.

Doctors at Tucson's University Medical Center said six of those shot, including Mr. Giffords, remain at the hospital. Although Ms. Giffords's condition has improved, she remains in an intensive care ward, and three other patients are in serious condition and two are in fair condition. "Everything is currently going well with all of those patients," Dr. Peter Rhee said.